Overview
ISO/TS 2597-4:2019 specifies a potentiometric titration method for the determination of total iron content in iron ores. The method uses potassium dichromate as titrant after reduction of Fe(III) with tin(II) chloride and titanium(III) chloride, with the excess reductant oxidized by dichromate. It applies to natural iron ores, concentrates and agglomerates (including sinter) with total iron from 29.04% to 72.02% by mass. The document also includes safety guidance and prescribes laboratory reagents, apparatus and result reporting.
Key topics and requirements
- Scope and applicability: Total iron content determination in ores and concentrates between 29.04% and 72.02% mass fraction; note limitations for samples containing >0.1% vanadium, copper or manganese.
- Analytical principle: Acid decomposition, reduction of Fe(III) to Fe(II), oxidation of excess reductant and potentiometric titration to end-point using an amperometric/potentiometric titrator with platinum electrodes.
- Reagents and standards: Defined reagent quality and preparation (e.g., hydrochloric, hydrofluoric, sulfuric acids; tin(II) and titanium(III) solutions; potassium dichromate and permanganate standard solutions).
- Apparatus and instrumentation: Requirements for volumetric glassware, muffle furnace, platinum electrodes, magnetic stirrers and an amperometric titrator with electrometric end-point detection.
- Sample preparation and decomposition: Laboratory sample prep, fusion and filtration procedures, and treatment steps prior to titration (including oxidation with permanganate and evaporation).
- Quality and precision: Procedures for blanks, check tests, hygroscopic moisture determination (referenced ISO 2596), repeatability, between-laboratory precision and acceptance of analytical values.
- Ancillary content: Flowsheet for acceptance of analytical values, electrode types, titration cell design, derivation of precision statements and a computer program for end-point detection (included as annexes).
Applications and users
- Laboratory and field quality control (QC) in mining and beneficiation operations.
- Chemical analysis laboratories performing metallurgical assays for iron ore concentrates, sinter and pellets.
- Accreditation bodies and testing labs that require a validated ISO method for reporting total iron content.
- Engineers and process control teams using accurate iron assays for blast-furnace feed planning and product specification.
Related standards
- ISO 2596 - hygroscopic moisture determination for analytical samples (referenced for moisture correction).
- ISO 7764 - preparation of predried test samples.
- ISO 3082 - sampling and sample preparation procedures for iron ores.
- ISO 648 / ISO 1042 - laboratory glassware specifications.
Keywords: ISO/TS 2597-4:2019, potentiometric titration method, total iron determination, iron ores, potassium dichromate, tin(II) chloride, titanium(III) chloride, analytical method, iron ore testing, laboratory quality control.